Tech Note: LIMTN023

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HP Z440/Z840 Power Management

Table of Contents

Introduction...............................................................................................................3

HP Z-Series Workstation Drivers..............................................................................3

BIOS Settings - HP Z440..........................................................................................3

BIOS Settings - HP Z840..........................................................................................4

BIOS Settings of Other PC Models and Manufacturers...........................................4

Windows 7 Power Options.......................................................................................5

Disabling C-States via Windows Registry................................................................6

Document Revisions.................................................................................................7

IntroductionTo comply with environmental regulations, computers are equipped with power-saving mechanisms. These mechanisms turn off different hardware parts (CPU, HDD), which may cause performance problems during long-lasting tasks.

For such tasks, the following power-saving options should be adjusted:

• BIOS power options

• MS Windows Power Options

• CPU power modes (C States or C Modes)which can be turned off either in BIOS or Windows REGISTRY

Depending on the manufacturer, adjusting the BIOS settings may change the corresponding settings in Windows 7 and vice versa. However, we recommend to make sure the settings are correctly set in all the places.

Caution

Some IT departments override the Windows Power Options settings when a domain-included computer starts, so you may want to verify that the settings persist after your PC reboots, or when you login under a different user account.

HP Z-Series Workstation DriversAll latest drivers for HP Z420/Z440/Z820/Z840 can be downloaded directly from the HP website:

http://support.hp.com/us-en/drivers

Warning: Before flashing your BIOS, please carefully read all attached information provided by the manufacturer.

In 2016, LIM QC used these versions of BIOS, Chipset and Driver storage drivers for testing HP Z420/Z440/Z820/Z840:

HP Z420

http://downloads.laboratory-imaging.com/NIS/4.5x/Z420.zip

HP Z440

http://downloads.laboratory-imaging.com/NIS/4.5x/Z440.zip

HP Z820

http://downloads.laboratory-imaging.com/NIS/4.5x/Z820.zip

HP Z840

http://downloads.laboratory-imaging.com/NIS/4.5x/Z840.zip

BIOS Settings - HP Z440BIOS version: 1.65

Enter BIOS by pressing F10 and set the following settings.

1. Go to the Advanced tab and click Power Options

2. Set the Power Options as displayed in the following image

◦ Runtime Power Options: Disable

◦ Idle Power Settings: Normal

◦ S4/S5 Max Power Savings: Disable

3. Return to the Main tab and save the changes:

BIOS Settings - HP Z840BIOS version: 1.65

Note: This procedure was tested on a dual-processor machine. A single-processor Z840 setup may differ.

Enter BIOS by pressing F10 and set the following settings:

1. Go to the Advanced tab and click Power Options

2. Set the Power Options as displayed in the followingimage:

◦ Enhanced Halt State (C1E): Disable

◦ S4/S5 Max Power Savings: Disable

3. Go back to the Advanced tab and set the Performance Options as displayed:

◦ Non-Uniform Memory Access (NUMA): Disable

◦ QPI Snoop Mode: Home Snoop

4. Return to the Main tab and save the changes:

BIOS Settings of Other PC Models and ManufacturersBIOS of other PC models / manufacturers will likely differ from the ones described. Here are some general rules which can help you:

1. Enter BIOS during startup of MS Windows. Please, consult the PC/motherboard manual or the "boot screen" on how to enter BIOS. It can be e.g. by pressing the F10 key.

2. Disable or toggle all power-management settings related to CPU Speed, USB and PCI/PCI-Express bus.

Example of setting names:

▪ SpeedStep

▪ Throttling

▪ Dynamic performance

▪ C-States Control

▪ Idle Power Savings (change this to "Normal")

3. Disable unused onboard devices. Computer motherboards can contain many built-in devices.which usually use resources even if they are not in operation. If you do not use them regularly, turn OFF all such devices:

◦ FireWire controllers

◦ WiFi controllers

◦ BlueTooth controllers

Windows 7 Power Options1. Click the Start menu and type/select Control Panel

2. Display the Power Options window. In Control Panel window, make sure the View by > Small Icons option is selected. Click Power Options.

3. To create your own power plan, click Create a power plan

4. A window appears, select High performance. Your power plan will be based on it. Name your power plan. Cick Next.

5. Click Create.

6. Your power plan appears in the list. Select it and click Change plan settings.

7. In the next window, click Change advanced power settings.

8. Set USB selective suspend setting to Disabled

9. Set Turn off hard disk after to 0. 0 stands for "Never".

10. Save and close all windows by the OK buttons

Settings Overview

The above procedure will work if the High performance power plan is in its factory setting. If you want to be sure,check whether all the following settings are set correctly:

Setting Value

Hard Disks > Turn off hard disk after Never (0)

Sleep > Sleep after Never (0)

USB Settings > USB selective suspend setting

Disabled

PCI Express > Link State Power Management

Off

Processor power management > Minimum processor state

100%

Disabling C-States via Windows Registry1. Log in to Windows with an administrator account

2. Download and run the following batch file:http://downloads.laboratory-imaging.com/NIS/4.5x/disableCstates.bat

3. Restart the computer

The batch file contains the following code:

@echo off

echo Disabling C States

reg add HKLM\System\CurrentControlSet\Control\Processor /v Capabilities /t REG_DWORD /d 0x0007e066

pause

Document Revisions16-March 2016 original version

14-February 2017 HP Z-Series Workstation Drivers chapter added